The word boner, accurately defined by Urban Dictionary as an “erect, blood-filled penis,” is inherently misleading. Where’s the bone in boner? Evidently, we’re just about the only mammals not possession of a penis bone, scientifically known as a baculum. Gorillas and chimps have one, and it assists in sexual reproduction by maintaining stiffness. Meanwhile, the baculum of a walrus is two-feet long. (It’s the most diverse bone in existence.) Feel inadequate yet?

When you go limp during sex, you have monogamy to thank. That’s not because you’re necessarily bored with your long-term partner, which is a story for another day. Scientists at University College London have discovered the bone began to disappear 1.9 million years ago, when one-on-one relationships became a thing. Men spent less time penetrating their females because they didn’t have to fret too much about other guys jumping her bones (that word again). Lazy!

Kat Opie, who led the study, told The Guardian: “With reduced competition for mates, you are less likely to need a baculum. Despite what we might want to think, we are actually one of the species that comes in below the three-minute cut-off where these things come in handy.”

Humans: Quicker and softer at sex than weasels and sea lions.